British Tidal Power Riding a Wave?

In a relentless search for alternatives to fossil fuel energy production, many scientists have turned to thinking about how to harness natural renewable forces to generate power.

Currently, the two leading contenders are solar and wind power but now, British scientists are attempting to harness the power of the moon to generate energy in the form of tidal power generators. If successful, tidal power could overcome the unpredictability of wind power and the limits of solar power from clouds and night time. Tides are so accurate and predictable that maritime nations have published timetables of them for more than 200 years.

Tidal power has been the poor stepsister of the two above mentioned renewable power sources because of its relatively high cost and the fact that current inefficient turbine designs have up to now limited the number of potential sites with sufficiently high tidal ranges or flow velocities.

If a British project succeeds however, that dynamic may be about to alter. Rolls-Royce, a renowned British engineering firm that has progressed from its initial automotive expertise into becoming a global power systems company, announced that its prototype subsea tidal turbine off the Orkney Islands in Scotland, has successfully generated and fed over 100 megawatt hours of electrical power into the national grid.

The Rolls-Royce prototype tidal turbine is part of the Deep-Gen III project, co-funded by the British government-backed Technology Strategy Board and is currently deployed at the European Marine Energy Center’s offshore test site off the Orkneys. The tidal unit’s three-bladed turbine is attached by a tripod to the seabed and can operate fully submerged at a depth of 130 feet.

Rolls-Royce Vice-President - Power Ventures Robert Stevenson said: “Rolls-Royce has injected its world-class engineering expertise and incubation processes to deliver this innovative renewable energy project. Reaching the 100 megawatt hour milestone highlights the significant potential of cleaner, greener tidal power as part of a diversified UK energy mix. Having proven the capability of tidal energy, Rolls-Royce is well placed to meet any future demand with larger, more efficient technology on a commercial scale.”

Tidal mills have been used, both in Europe and on the Atlantic coast of North America, with the usage dating from the Middle Ages, although some archaeologist place using tidal power back to Roman times.

Europe’s interest in the potential of tidal power is longstanding since France’s L’Usine Maremotrice de la Rance (Rance Tidal Power Station), the world’s first large-scale tidal power plant, became operational in 1966. The Rance Tidal Power Station, currently the world’s second biggest tidal power station, is situated on the estuary of the Rance River, in Brittany, France. Operated by Electricite de France, the Rance Tidal Power Station has a peak rating of 240 megawatts, generated by 24 turbines.

If fully deployed, Rolls-Royce predicts that its tidal technology could generate up to 30 terawatt-hours of British electricity, equivalent to around 7.5 per cent of current British electricity needs, enough to power 3 million homes.

British Technology Strategy Board head of energy Neil Morgan remarked of the Rolls Royce effort, “This is a significant milestone for the U.K. marine renewables industry. The UK is well-placed to exploit tidal stream energy resources and, if commercialized on a large scale, this technology could be an important part of the renewable energy mix we'll need in the future, and could create jobs and exports for the U.K.”

But Rolls Royce cannot rest on its laurels. Beside France’s Rance facility, countries currently operating tidal wave power projects include Britain’s earlier Strangford Lough Seagen facility, Canada’s Annapolis Royal Generating Station, China’s Jiangxia Tidal Power Station, Russia’s Kislaia Guba Tidal Power Station, South Korea’s Sihwa Lake Tidal Power Station and Uldolmok Tidal Power Station and the country is currently building a third tidal power facility, the Inchon Tidal Power Station. The Philippines and India are also considering building tidal power facilities.

In a historical irony, Inchon’s high tides were a major factor in American General Douglas MacArthur’s amphibious landings there in September 1950, which helped turn the tide of the Korean War.

But that was sixty years ago, and the oceanic conditions that once so bedeviled military planners may now be used to light peaceful coastlines.